Low friction instrument driver interface for robotic systems

ABSTRACT

A medical robotic system includes a base having a first opening, and a first protrusion next to the first opening, a first rotary member configured for detachably coupling to a component of the medical robotic system in a manner such that the first rotary member is rotatable relative to the base and at least a part of the first rotary member is located in the first opening of the base when the first rotary member is coupled to the system component, and a cover coupled to the base, wherein the first rotary member comprises a first end, a second end, a body extending between the first and second ends, and a flange disposed circumferentially around a part of the body, the flange having a first circumferential slot for receiving the first protrusion.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.15/228,743, filed Aug. 4, 2016, and entitled “LOW FRICTION INSTRUMENTDRIVER INTERFACE FOR ROBOTIC SYSTEMS,” issued as U.S. Pat. No.11,147,637 on Oct. 19, 2021, and which is a continuation of U.S. patentapplication Ser. No. 13/481,536, filed May 25, 2012, and entitled “LOWFRICTION INSTRUMENT DRIVER INTERFACE FOR ROBOTIC SYSTEMS,” nowabandoned, the entirety of which is herein incorporated by reference forall purposes.

INCORPORATION BY REFERENCE

All of the following U.S. patent applications are expressly incorporatedby reference herein for all purposes:

U.S. patent application Ser. No. 13/173,994, filed on Jun. 30, 2011,issued as U.S. Pat. No. 8,827,948 on Sep. 9, 2014,

U.S. patent application Ser. No. 11/179,007, filed on Jul. 6, 2005,issued as U.S. Pat. No. 7,580,642 on Dec. 14, 2010,

U.S. patent application Ser. No. 12/079,500, filed on Mar. 26, 2008,issued as U.S. Pat. No. 8,391,957 on Mar. 5, 2013,

U.S. patent application Ser. No. 11/678,001, filed on Feb. 22, 2007,issued as U.S. Pat. No. 8,092,397 on Jan. 10, 2012,

U.S. Patent Application No. 60/801,355, filed on May 17, 2006,

U.S. patent application Ser. No. 11/804,585, filed on May 17, 2007, nowabandoned,

U.S. patent application Ser. No. 11/640,099, filed on Dec. 14, 2006,issued as U.S. Pat. No. 8,498,691 on Jul. 30, 2013,

U.S. patent application Ser. No. 12/507,727, filed on Jul. 22, 2009, nowabandoned,

U.S. patent application Ser. No. 12/106,254, filed on Apr. 18, 2008,issued as U.S. Pat. No. 8,050,523 on Nov. 1, 2011,

U.S. patent application Ser. No. 12/192,033, filed on Aug. 14, 2208,issued as U.S. Pat. No. 9,186,046 on Nov. 17, 2015,

U.S. patent application Ser. No. 12/236,478, filed on Sep. 23, 2008,issued as U.S. Pat. No. 8,989,528 on Mar. 24, 2015,

U.S. patent application Ser. No. 12/833,935, filed on Jul. 9, 2010, nowabandoned,

U.S. patent application Ser. No. 12/822,876, filed on Jun. 24, 2010,issued as U.S. Pat. No. 8,460,236 on Jun. 11, 2013,

U.S. patent application Ser. No. 12/614,349, filed on Nov. 6, 2009,issued as U.S. Pat. No. 8,720,448 on May 13, 2014,

U.S. patent application Ser. No. 11/690,116, filed Mar. 22, 2007, nowabandoned,

U.S. patent application Ser. No. 11/176,598, filed Jul. 6, 2005, nowabandoned,

U.S. patent application Ser. No. 12/012,795, filed Feb. 1, 2008, nowabandoned,

U.S. patent application Ser. No. 12/837,440, Jul. 15, 2010, issued asU.S. Pat. No. 8,780,339 on Jul. 15, 2014,

U.S. Patent Application No. 61/513,488, filed Jul. 8, 2011, and

U.S. patent application Ser. No. 13/174,605, filed Jun. 30, 2011, issuedas U.S. Pat. No. 9,314,306 on Apr. 19, 2016.

FIELD

The application relates generally to robotically controlled surgicalsystems, and more particularly to flexible instruments and instrumentdrivers that are responsive to a master controller for performingsurgical procedures to treat tissue, such as tissue in the livers.

BACKGROUND

Robotic surgical systems and devices are well suited for use inperforming minimally invasive medical procedures, as opposed toconventional techniques wherein the patient's body cavity is open topermit the surgeon's hands access to internal organs. For example, thereis a need for a highly controllable yet minimally sized system tofacilitate imaging, diagnosis, and treatment of tissues which may liedeep within a patient, and which may be preferably accessed only vianaturally-occurring pathways such as blood vessels or thegastrointestinal tract.

In some cases, a robotic surgical system may include a steerablecatheter with a steering wire, and an instrument driver for applyingtension to the steering wire to steer the catheter. Applicant of thesubject application determines that it would be desirable to sense acharacteristic that corresponds with an amount of force or torque beingapplied to pull a steering wire of a robotic surgical system.

SUMMARY

In accordance with some embodiments, a medical robotic system includes abase having a first opening, and a first protrusion next to the firstopening, a first rotary member configured for detachably coupling to acomponent of the medical robotic system in a manner such that the firstrotary member is rotatable relative to the base and at least a part ofthe first rotary member is located in the first opening of the base whenthe first rotary member is coupled to the system component, and a covercoupled to the base, wherein the first rotary member comprises a firstend, a second end, a body extending between the first and second ends,and a flange disposed circumferentially around a part of the body, theflange having a first circumferential slot for receiving the firstprotrusion.

In accordance with other embodiments, a medical robotic system includesan instrument driver having an actuatable element, a sensor coupled tothe instrument driver, and a device configured for detachably couplingto the instrument driver, the device comprising a base having a firstopening, and a rotary member configured for detachably coupling to theactuatable element of the instrument driver, wherein the rotary memberis rotatable relative to the base, and at least a portion of the rotarymember is located within the first opening of the base, wherein when thedevice is coupled to the instrument driver, the actuatable element isconfigured to rotate the rotary member in response to a command signalreceived from a user interface, and wherein the sensor is configured tosense a characteristic that corresponds with an amount of force ortorque being applied to the actuatable element in order to rotate therotary member.

In accordance with other embodiments, a method of steering a distal endof an elongate member includes determining a desired bending to beachieved by the distal end of the elongate member, determining an amountof tension to be applied to a steering wire located within the elongatemember based on the desired bending to be achieved, using an actuatableelement to apply a torque to turn a rotary member that is detachablycoupled to the actuatable element, the steering wire having one end issecured to the rotary member and another end secured to the elongatemember, wherein the application of the torque by the actuatable elementcauses tension to be applied to the steering wire, and using a sensorcoupled to the actuatable element to sense a characteristic thatcorresponds with an amount of force or torque being applied by theactuatable element to turn the rotary member.

Other and further aspects and features will be evident from reading thefollowing detailed description of the embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate the design and utility of embodiments, in whichsimilar elements are referred to by common reference numerals. Thesedrawings are not necessarily drawn to scale. In order to betterappreciate how the above-recited and other advantages and objects areobtained, a more particular description of the embodiments will berendered, which are illustrated in the accompanying drawings. Thesedrawings depict only typical embodiments and are not therefore to beconsidered limiting of its scope.

FIG. 1 illustrates a robotic surgical system in which apparatus, systemand method embodiments may be implemented.

FIG. 2 illustrates how the adapter base plate assembly is utilized toattach a support assembly and instrument driver to an operating table orsurgical bed.

FIG. 3 a sheath and guide catheter assembly, and an elongate membermanipulator mounted on an instrument driver

FIG. 4 illustrates an example of an operator workstation of the roboticsurgical system shown in FIG. 1 with which a catheter instrument can bemanipulated using different user interfaces and controls.

FIG. 5A further illustrates the instrument driver shown in FIG. 3without the elongate member manipulator mounted on an instrument driver.

FIG. 5B further illustrates the instrument driver shown in FIG. 5Awithout the sheath and guide catheter assembly.

FIG. 5C further illustrates the instrument driver shown in FIG. 5B withskins removed.

FIGS. 6A and 6B illustrate a sheath and guide catheter assemblypositioned over respective sterile adaptors and mounting plates from topand bottom perspectives respectively

FIGS. 7A and 7B illustrate top and bottom perspectives respectively of aportion of an instrument driver with a sheath splayer positioned over asterile adaptor.

FIG. 7C illustrates an exploded view of the sheath splayer shown in FIG.7A without a purge tube.

FIG. 7D illustrates top and bottom views of a pulley assembly positionedover a floating shaft.

FIG. 7E illustrates the floating shaft of FIG. 7D installed andun-installed onto a sleeve receptacle.

FIG. 8 illustrates a guide carriage of the instrument driver shown inFIG. 5C with pulleys and guide articulation motors.

FIG. 9 is a perspective view of a slidable carriage or funicularassembly of an instrument driver and sleeve receptacles configured toreceive and engage with floating shafts.

FIG. 10 illustrates a sheath block, sheath insert motor, guide insertmotor and leadscrews removed from the instrument driver shown in FIG.5C.

FIGS. 10A and 10B illustrate different perspective views of the sheathblock with sheath output plate positioned over receptacle sleeves.

FIG. 10C illustrates sheath articulation motors coupled to motor driveninterfaces and receptacle sleeves.

FIGS. 11A-11H illustrate side and cross-sectional views of a catheterbent in various configurations with pull wire manipulation.

FIG. 12 illustrates an open loop control model.

FIG. 13 illustrates a control system in accordance with someembodiments.

FIG. 14 illustrates a user interface for a master input device.

FIG. 15 illustrates some components of a robotic system that includestension sensing capability in accordance with some embodiments;

FIG. 16 illustrates some components of a robotic system that includestension sensing capability in accordance with other embodiments;

FIG. 17 illustrates some components of a robotic system that includestension sensing capability in accordance with other embodiments;

FIG. 18 illustrates a frictionless interface at a sterile adaptor inaccordance with some embodiments;

FIG. 19 illustrates some components of a robotic system that includestension sensing capability in accordance with other embodiments;

FIG. 20 illustrates some components of a robotic system that includestension sensing capability in accordance with other embodiments;

FIG. 21 illustrates some components of a robotic system that includestension sensing capability in accordance with other embodiments;

FIG. 22A illustrates driving mode(s) in accordance with someembodiments.

FIG. 22B illustrates driving mode(s) in accordance with otherembodiments.

FIG. 22C illustrates driving mode(s) in accordance with otherembodiments.

FIG. 22D illustrates driving mode(s) in accordance with otherembodiments.

FIG. 23A-23F illustrates a method of using a robotic system to treattissue in accordance with some embodiments.

DESCRIPTION OF THE EMBODIMENTS

Various embodiments are described hereinafter with reference to thefigures. It should be noted that the figures are not drawn to scale andthat elements of similar structures or functions are represented by likereference numerals throughout the figures. It should also be noted thatthe figures are only intended to facilitate the description of theembodiments. They are not intended as an exhaustive description of theinvention or as a limitation on the scope of the invention. In addition,an illustrated embodiment needs not have all the aspects or advantagesshown. An aspect or an advantage described in conjunction with aparticular embodiment is not necessarily limited to that embodiment andcan be practiced in any other embodiments even if not so illustrated.

I. Robotic System

Embodiments described herein generally relate to apparatus, systems andmethods for robotic surgical systems. A robotic surgical system in whichembodiments described herein may be implemented is described withreference to FIGS. 1-10C.

Referring to FIG. 1, a robotically controlled surgical system 10 inwhich embodiments of apparatus, system and method may be implementedincludes an operator workstation 2, an electronics rack 6 and associatedbedside electronics box 9, a setup joint or support assembly 20(generally referred to as “support assembly”), and a robotic instrumentdriver 16 (generally referred to as “instrument driver”). A surgeon isseated at the operator workstation 2 and can monitor the surgicalprocedure, patient vitals, and control one or more robotic surgicaldevices.

Referring to FIG. 2, the instrument driver 16, setup joint mountingbrace 20, and bedside electronics box are shown in greater detail.Referring to FIG. 3, the instrument driver 16 is illustrated includingan elongate member manipulator 24 and a robotic catheter assembly 11installed. The robotic catheter assembly 11 includes a first or outerrobotic steerable complement, otherwise referred to as a sheathinstrument 30 (generally referred to as “sheath” or “sheath instrument”)and/or a second or inner steerable component, otherwise referred to as arobotic catheter or guide or catheter instrument 18 (generally referredto as “catheter” or “catheter instrument”). The sheath instrument 30 andcatheter instrument 18 are controllable using the instrument driver 16.During use, a patient is positioned on an operating table or surgicalbed 22 (generally referred to as “operating table”) to which the supportassembly 20, instrument driver 16, and robotic catheter assembly 11 arecoupled or mounted.

In the illustrated embodiments, the elongate member manipulator 24(generally referred to as “manipulator”) is configured for manipulatingan elongate member 26. In some embodiments, the elongate member 26 maybe a guidewire. In other embodiments, the elongate member 26 may be atreatment device (e.g., an ablation catheter) that is configured todeliver energy to treat tissue, such as tissue at a liver. In furtherembodiments, the elongate member 26 may be any of other instruments formedical use. During use, at least a part of the elongate member 26 isdisposed within a lumen of the catheter instrument 18, and the proximalend of the elongate member 26 is removably coupled to the manipulator24. In some embodiments, the manipulator 24 is configured to advance andretract the elongate member 26 relative to the catheter instrument 18.In other embodiments, the manipulator 24 may also be configured to rollthe elongate member 26 so that it rotates about its longitudinal axis.

Various system components in which embodiments described herein may beimplemented are illustrated in close proximity to each other in FIG. 1,but embodiments may also be implemented in systems 10 in whichcomponents are separated from each other, e.g., located in separaterooms. For example, the instrument driver 16, operating table 22, andbedside electronics box 9 may be located in the surgical area with thepatient, and the operator workstation 2 and the electronics rack 6 maybe located outside of the surgical area and behind a shielded partition.System 10 components may also communicate with other system 10components via a network to allow for remote surgical procedures duringwhich the surgeon may be located at a different location, e.g., in adifferent building or at a different hospital utilizing a communicationlink transfers signals between the operator control station 2 and theinstrument driver 16. System 10 components may also be coupled togethervia a plurality of cables or other suitable connectors 14 to provide fordata communication, or one or more components may be equipped withwireless communication components to reduce or eliminate cables 14. Inthis manner, a surgeon or other operator may control a surgicalinstrument while being located away from or remotely from radiationsources, thereby decreasing the operator's exposure to radiation.

Referring to FIG. 4, one example of an operator workstation 2 that maybe used with the system 10 shown in FIG. 1 includes three displayscreens 4, a touch screen user interface 5, a control button console orpendant 8, and a master input device (MID) 12. The MID 12 and pendant 8serve as user interfaces through which the surgeon can control operationof the instrument driver 16 and attached instruments. By manipulatingthe pendant 8 and the MID 12, a surgeon or other operator can cause theinstrument driver 16 to remotely control the catheter instrument 18and/or the sheath instrument 30 mounted thereon. Also, in someembodiments, by manipulating one or more controls at the station 2, thesurgeon or operator may cause the manipulator 24 to remotely move theelongate member 26. A switch 7 may be provided to disable activity of aninstrument temporarily. The console 2 in the illustrated system 10 mayalso be configurable to meet individual user preferences. For example,in the illustrated example, the pendant 8 and the touch screen 5 areshown on the left side of the console 2, but they may also be relocatedto the right side of the console 2. Various numbers of display screensmay be provided. Additionally or alternatively, a bedside console 3 maybe provided for bedside control of the of the instrument driver 16 ifdesired. Further, optional keyboard may be connected to the console 2for inputting user data. The workstation 2 may also be mounted on a setof casters or wheels to allow easy movement of the workstation 2 fromone location to another, e.g., within the operating room or catheterlaboratory. Further aspects of examples of suitable MID 12, andworkstation 2 arrangements are described in further detail in U.S.patent application Ser. No. 11/481,433, issued as U.S. Pat. No.8,052,636 on Nov. 8, 2011, and U.S. Provisional Patent Application No.60/840,331, the contents of which were previously incorporated herein byreference.

As shown in FIG. 1, the support assembly 20 is configured for supportingor carrying the instrument driver 16 over the operating table 22. Onesuitable support assembly 20 has an arcuate shape and is configured toposition the instrument driver 16 above a patient lying on the table 22.The support assembly 20 may be configured to movably support theinstrument driver 16 and to allow convenient access to a desiredlocation relative to the patient. The support assembly 20 may also beconfigured to lock the instrument driver 16 into a certain position.

In the illustrated example, the support assembly 20 is mounted to anedge of the operating table 22 such that a catheter and sheathinstruments 18, 30 mounted on the instrument driver 16 can be positionedfor insertion into a patient. The instrument driver 16 is controllableto maneuver the catheter and/or sheath instruments 18, 30 within thepatient during a surgical procedure. The distal portion of the setupjoint 20 also includes a control lever 33 for maneuvering the setupjoint 20. Although the figures illustrate a single guide catheter 18 andsheath assembly 30 mounted on a single instrument driver 16, embodimentsmay be implemented in systems 10 having other configurations. Forexample, embodiments may be implemented in systems 10 that include aplurality of instrument drivers 16 on which a plurality ofcatheter/sheath instruments 18, 30 can be controlled. Further aspects ofa suitable support assembly 20 are described in U.S. patent applicationSer. No. 11/481,433, issued as U.S. Pat. No. 8,052,636 on Nov. 8, 2011,and U.S. Provisional Patent Application No. 60/879,911, the contents ofwhich are expressly incorporated herein by reference. Referring to FIG.2, the support assembly 20 may be mounted to an operating table 22 usinga universal adapter base plate assembly 39, similar to those describedin detail in U.S. Provisional Patent Application No. 60/899,048,incorporated by reference herein in its entirety. The adapter plateassembly 39 mounts directly to the operating table 22 using clampassemblies, and the support assembly 20 may be mounted to the adapterplate assembly 39. One suitable adapter plate assembly 39 includes twolarge, flat main plates which are positioned on top of the operatingtable 22. The assembly 39 provides for various adjustments to allow itto be mounted to different types of operating tables 22. An edge of theadapter plate assembly 39 may include a rail that mimics theconstruction of a traditional surgical bedrail. By placing this rail onthe adapter plate itself, a user may be assured that the componentdimensions provide for proper mounting of the support assembly 20.Furthermore, the large, flat surface of the main plate providesstability by distributing the weight of the support assembly 20 andinstrument driver 16 over an area of the table 22, whereas a supportassembly 20 mounted directly to the operating table 22 rail may causeits entire load to be placed on a limited and less supportive section ofthe table 22. Additionally or alternatively, a bedside rail 13 may beprovided which may couple the support assembly 20 to the operating table22. The bedside rail may include a leadscrew mechanism which will enablethe support assembly to translate linearly along the edge of the bed,resulting in a translation of the instrument driver 16 and ultimately atranslation in the insert direction of the catheter and sheathinstruments 18/30.

FIGS. 5A-C illustrate the instrument drive 16 with various componentsinstalled. FIG. 5A illustrates the instrument driver 16 with theinstrument assembly 11 installed including the sheath instrument 30 andthe associated guide or catheter instrument 18 while FIG. 5B illustratesthe instrument driver 16 without an attached instrument assembly 11. Thesheath instrument 30 and the associated guide instrument 18 are mountedto associated mounting plates 37, 38 on a top portion of the instrumentdriver 16. FIG. 5C illustrates the instrument driver 16 with skinsremoved to illustrate internal components. Embodiments described aresimilar to those described in detail in U.S. patent application Ser.Nos. 11/678,001, issued as U.S. Pat. No. 8,092,397 on Jan. 10, 2012,11/678,016, issued as U.S. Pat. No. 8,052,621 on Nov. 8, 2011, and11/804,585, now abandoned, each incorporated by reference herein in itsentirety.

Referring to FIGS. 6A-B, the assembly 11 that includes the sheathinstrument 30 and the guide or catheter instrument 18 positioned overtheir respective mounting plates 38, 37 is illustrated removed from theinstrument driver 16. Additionally a sterile adaptor 41 can be used tocouple each of the sheath and guide instruments to their respectivemounting plates. The catheter instrument 18 includes a guide catheterinstrument member 61 a, and the sheath instrument 30 includes a sheathinstrument member 62 a. The guide catheter instrument member 61 a iscoaxially interfaced with the sheath instrument member 62 a by insertingthe guide catheter instrument member 61 a into a working lumen of thesheath catheter member 62 a. As shown in FIG. 6A, the sheath instrument30 and the guide or catheter instrument 18 are coaxially disposed formounting onto the instrument driver 16. However, it should be understoodthat the sheath instrument 16 may be used without a guide or catheterinstrument 18, or the guide or catheter instrument 18 may be usedwithout a sheath instrument 30. In such cases, the sheath instrument 16or the catheter instrument 18 may be mounted onto the instrument driver16 individually. With the coaxial arrangement as shown in FIG. 6A, aguide catheter splayer 61 is located proximally relative to, or behind,a sheath splayer 62 such that the guide catheter member 61 a can beinserted into and removed from the sheath catheter member 61 b.

The splayers 61, 62 are configured to steer the members 61 a, 61 b,respectively. In the illustrated embodiments, each of the splayers 61,62 includes drivable elements therein configured to apply tension todifferent respective wires inside the member 61 a/61 b to thereby steerthe distal end of the member 61 a/61 b. In some embodiments, thedrivable elements may be actuated in response to a control signal from acontroller, which receives an input signal from the work station 2, andgenerates the control signal in response to the input signal. Also, inthe illustrated embodiments, the splayers 61, 62 may be translatedrelative to the instrument driver 16. In some embodiments, theinstrument driver 16 may be configured to advance and retract each ofthe splayers 61, 62, so that the catheter instrument 18 and the sheathinstrument 30 may be advanced distally and retracted proximally.

FIGS. 7A and 7B illustrate the sheath splayer 62 of one embodimentillustrated with the sterile adaptor 41 and mounting plate 38 coupled toa portion of the instrument driver shown with only a set of actuationmechanisms that will be described later in detail. As shown in FIG. 6A,the sheath and guide splayers 62, 61, appear similar physically inconstruction with the exception of differences in a valve purge tube 32.It should be noted that the purge tube 32 may or may not be included foreither the guide or sheath splayer. The sheath splayer 62 will bedescribed herein. However it should be understood that the guide splayer61 is of similar construction, and components of the sheath splayer 62can be repeated for the guide splayer 61.

As illustrated in FIG. 7C, the splayer 62 includes a splayer cover 72fixably coupled to a splayer base assembly 78 using four screws 79. Thesplayer base 78 having four cavities to receive and house pulleyassemblies 80 is used for both the guide splayer 61 and sheath splayer62. For this embodiment of a sheath splayer 62, four cavities of thesplayer base 78 are populated with pulley assemblies 80 but it should beunderstood that varying numbers of cavities may be populated leavingremaining cavities open. The guide splayer 61 may have all its cavitiespopulated with four pulley assemblies 80 for pulling four respectivewires, as can be seen in FIG. 6B. The splayer base 78 of thisimplementation can be constructed from injection molded polycarbonate.

During splayer 62 assembly, the pulley assembly 80 is put together andmated with a catheter pull wire or control element (not shown). The pullwire (not shown) runs down the length of a catheter from distal toproximal end then is wound about the pulley. By rotating the pulley, thepull wire bends the distal tip of the catheter controlling its bend.

Referring back to FIGS. 6A-6B, when a catheter is prepared for use withan instrument, its splayer is mounted onto its appropriate mountingplate via a sterile adaptor. In this case, the sheath splayer 62 isplaced onto the sheath mounting plate 38 and the guide splayer 61 isplace onto the guide mounting plate 37 via sterile adaptors 41.Referring to FIG. 7A-B, the pulley assemblies 80 are configured tocouple to floating shafts 82 on the splayer adaptor 41 which in turn areconfigured to couple to sleeve receptacles 90. In the illustratedexample, each mounting plates 37, 38 has four openings 37 a, 38 a thatare designed to receive the corresponding floating shafts 84 attached toand extending from the sterile adaptors 41 coupled to the splayers 61,62. In the example illustrated in FIG. 6B, four floating shafts 82 ofthe sterile adaptor 41 are insertable within the openings 38 a of thesheath mounting plate 38 as the splayer 62 is mounted onto the RCM.Similarly, four floating shafts 82 of the sterile adaptor 41 areinsertable within the four apertures or openings 37 a of the guideinterface plate 37. Referring to FIGS. 7D-E, the coupling of the pulleyassemblies 80 to floating shafts 82 and floating shafts 82 to sleevereceptacles 90 is illustrated. FIG. 7D illustrates top and bottomperspective views of the pulley assembly 80 positioned above thefloating shaft 82 where the bottom of the pulley assembly 80 isconfigured to mate with splines on the top of the floating shaft 82.FIG. 7E illustrates the floating shaft 82 installed and un-installedonto the sleeve receptacle 90. The sleeve receptacles can include anotch 90 a shaped to accept a pin 84 on the floating shaft 82.

Referring back to FIGS. 7A-B, the sheath splayer 62 is shown havinglatches 73 which may couple to hooks 86. By depressing the latches 73,the splayer 62 may be locked and unlocked to the sterile adaptor 41. Thesterile adaptor in turn is configured having mounting hooks 88 whichcouple to sliding latches 77 on the mounting plate 83. The slidinglatches 77 can be spring loaded to allow the adaptor plate 41 to belocked to the mounting plate 38 by applying downward force on theadaptor plate 41. The sliding latches can be depressed to release theadaptor plate 41 when desired.

The sheath interface mounting plate 38 as illustrated in FIGS. 6A and 6Bis similar to the guide interface mounting plate 37, and thus, similardetails are not repeated. One difference between the plates 37, 38 maybe the shape of the plates. For example, the guide interface plate 37includes a narrow, elongated segment, which may be used with, forexample, a dither mechanism or the elongate member manipulator 24. Bothplates 37, 38 include a plurality of openings 37 a, 38 a to receivefloating shafts 82 and latches 73 from sterile adaptors 41. The splayers61/62, sterile adaptors 41, and mounting plates 37/38 are all describedin greater detail in U.S. patent application Ser. No. 13/173,994, filedon Jun. 30, 2011, issued as U.S. Pat. No. 8,827,948 on Sep. 9, 2014, theentire disclosure of which is expressly incorporated by referenceherein.

Referring back to FIG. 5C the instrument driver 16 is illustrated withmounting plates 37,38 fixably coupled to a guide carriage 50, and asheath drive block 40, respectively. FIG. 8 illustrates the guidecarriage 50 removed from the instrument driver 16 coupled to cabling(not shown) and associated guide motors 53. The guide carriage 50includes a funicular assembly 56 which is illustrated in FIG. 9. Thefunicular assembly 56 includes the four sleeve receptacles 90. Aspreviously described, the floating shafts 82 of the sterile adaptor 41first insert through the openings 37 a in the mounting plate 37. Theythen engage with the sleeve receptacles 90

Referring back to FIG. 8, a set of cables (not shown) wound around a setof pulleys 52, are coupled on one end to a set of guide motors 53 andthe other end to the sleeve receptacles 90. Note that only two of fourmotors can be seen in FIG. 8. The drive motors 53 are actuated torotationally drive the sleeves 90. The catheter assembly 18 with itssplayer 61 mounted onto the instrument drive 16 would have its pulleyassemblies 80 coupled to corresponding sleeves 90 via floating shafts82. As the sleeves 90 are rotated, the pins 84 of the floating shafts 82are seated in the V-shaped notches and are engaged by the rotatingsleeves 90, thus causing the floating shafts 82 and associated pulleyassemblies 80 to also rotate. The pulley assemblies 80 in turn cause thecontrol elements (e.g., wires) coupled thereto to manipulate the distaltip of the catheter instrument 30 member in response thereto. FIGS. 10Aand 10B illustrate top and bottom perspective views of the sheath outputplate 38 exploded from the sheath block 40 and motor driven interfaces42 which are coupled to sheath articulation motors 43. FIG. 10Cillustrates sheath articulation motors 43 coupled to the motor driveninterfaces 42 which includes a set of belts, shafts, and gears whichdrive receptacle sleeves 90 (which are similar in construction andfunctionality to the receptacle sleeves previously described for theguide funicular assembly). When the sheath splayer pulley assemblies 80and sterile adaptor floating shafts 82 are coupled to the receptaclesleeves 90, the sheath articulation motors 43 drive the receptaclesleeves 90 causing the sheath instrument 30 to bend in the same mannerdescribed for the guide instrument.

During use, the catheter instrument 18 is inserted within a centrallumen of the sheath instrument 30 such that the instruments 18, 30 arearranged in a coaxial manner as previously described. Although theinstruments 18, 30 are arranged coaxially, movement of each instrument18, 30 can be controlled and manipulated independently. For thispurpose, motors within the instrument driver 16 are controlled such thatthe drive and sheath carriages coupled to the mounting plates 37, 38 aredriven forwards and backwards independently on linear bearings each withleadscrew actuation. FIG. 10 illustrates the sheath drive block 40removed from the instrument driver coupled to two independently-actuatedlead screw 45, 46 mechanisms driven by guide and sheath insert motors 47a, 47 b. Note the guide carriage is not shown. In the illustratedembodiment, the sheath insertion motor 47 b is coupled to a sheathinsert leadscrew 46 that is designed to move the sheath articulationassembly forwards and backwards, thus sliding a mounted sheath catheterinstrument (not shown) forwards and backwards. The insert motion of theguide carriage can be actuated with a similar motorized leadscrewactuation where a guide insert motor 47 a is coupled to the guide insertleadscrew 45 via a belt.

Referring back to FIGS. 1, 4 and 6A, in order to accurately steer therobotic sheath 62 a or guide catheter 61 a from an operator work station2, a control structure may be implemented which allows a user to sendcommands through input devices such as the pendant 8 or MID 12 that willresult in desired motion of the sheath 62 a and guide 61 a. In someembodiments, the sheath 62 a and/or the guide 61 a may each have fourcontrol wires for bending the instrument in different directions.Referring to FIGS. 11A-H, the basic kinematics of a catheter 120 withfour control elements 122 a, 122 b, 122 c, 122 d is shown. The catheter120 may be component 61 a or component 62 a in some embodiments.Referring to FIGS. 11A-B, as tension is placed only upon the bottomcontrol element 122 c, the catheter bends downward, as shown in FIG.11A. Similarly, pulling the left control element 122 d in FIGS. 11C-Dbends the catheter left, pulling the right control element 122 b inFIGS. 11E-F bends the catheter right, and pulling the top controlelement 122 a in FIGS. 11G-H bends the catheter up. As will be apparentto those skilled in the art, well-known combinations of applied tensionabout the various control elements results in a variety of bendingconfigurations at the tip of the catheter member 120.

The kinematic relationships for many catheter instrument embodiments maybe modeled by applying conventional mechanics relationships. In summary,a control-element-steered catheter instrument is controlled through aset of actuated inputs. In a four-control-element catheter instrument,for example, there are two degrees of motion actuation, pitch and yaw,which both have +and − directions. Other motorized tension relationshipsmay drive other instruments, active tensioning, or insertion or roll ofthe catheter instrument. The relationship between actuated inputs andthe catheter's end point position as a function of the actuated inputsis referred to as the “kinematics” of the catheter.

To accurately coordinate and control actuations of various motors withinan instrument driver from a remote operator control station such as thatdepicted in FIG. 1, a computerized control and visualization system maybe employed. The control system embodiments that follow are described inreference to a particular control systems interface, namely theSimuLink™ and XPC™ control interfaces available from The Mathworks Inc.,and PC-based computerized hardware configurations. However, one ofordinary skilled in the art having the benefit of this disclosure wouldappreciate that many other control system configurations may beutilized, which may include various pieces of specialized hardware, inplace of more flexible software controls running on one or more computersystems.

FIGS. 12-13 illustrate examples of a control structure for moving thecatheter 61 a and/or the sheath 62 a in accordance with someembodiments. In one embodiment, the catheter (or other shapeableinstrument) is controlled in an open-loop manner as shown in FIG. 12. Inthis type of open loop control model, the shape configuration commandcomes in to the beam mechanics, is translated to beam moments andforces, then is translated to tendon tensions given the actuatorgeometry, and finally into tendon displacement given the entire deformedgeometry.

Referring to FIG. 13, an overview of other embodiment of a controlsystem flow is depicted. A master computer 400 running master inputdevice software, visualization software, instrument localizationsoftware, and software to interface with operator control stationbuttons and/or switches is depicted. In one embodiment, the master inputdevice software is a proprietary module packaged with an off-the-shelfmaster input device system, such as the Phantom™ from Sensible DevicesCorporation, which is configured to communicate with the Phantom™hardware at a relatively high frequency as prescribed by themanufacturer. Other suitable master input devices, such as the masterinput device 12 depicted in FIG. 2 are available from suppliers such asForce Dimension of Lausanne, Switzerland. The master input device 12 mayalso have haptics capability to facilitate feedback to the operator, andthe software modules pertinent to such functionality may also beoperated on the master computer 126.

Referring to FIG. 13, in one embodiment, visualization software runs onthe master computer 126 to facilitate real-time driving and navigationof one or more steerable instruments. In one embodiment, visualizationsoftware provides an operator at an operator control station, such asthat depicted in FIG. 2, with a digitized “dashboard” or “windshield”display to enhance instinctive drivability of the pertinentinstrumentation within the pertinent tissue structures. Referring toFIG. 14, a simple illustration is useful to explain one embodiment of apreferred relationship between visualization and navigation with amaster input device 12. In the depicted embodiment, two display views142, 144 are shown. One preferably represents a primary 142 navigationview, and one may represent a secondary 144 navigation view. Tofacilitate instinctive operation of the system, it is preferable to havethe master input device coordinate system at least approximatelysynchronized with the coordinate system of at least one of the twoviews. Further, it is preferable to provide the operator with one ormore secondary views which may be helpful in navigating throughchallenging tissue structure pathways and geometries.

Referring still to FIG. 14, if an operator is attempting to navigate asteerable catheter in order to, for example, contact a particular tissuelocation with the catheter's distal tip, a useful primary navigationview 142 may comprise a three dimensional digital model of the pertinenttissue structures 146 through which the operator is navigating thecatheter with the master input device 12, along with a representation ofthe catheter distal tip location 148 as viewed along the longitudinalaxis of the catheter near the distal tip. This embodiment illustrates arepresentation of a targeted tissue structure location 150, which may bedesired in addition to the tissue digital model 146 information. Auseful secondary view 144, displayed upon a different monitor, in adifferent window upon the same monitor, or within the same userinterface window, for example, comprises an orthogonal view depictingthe catheter tip representation 148, and also perhaps a catheter bodyrepresentation 152, to facilitate the operator's driving of the cathetertip toward the desired targeted tissue location 150.

In one embodiment, subsequent to development and display of a digitalmodel of pertinent tissue structures, an operator may select one primaryand at least one secondary view to facilitate navigation of theinstrumentation. By selecting which view is a primary view, the user canautomatically toggle a master input device 12 coordinate system tosynchronize with the selected primary view. In an embodiment with theleftmost depicted view 142 selected as the primary view, to navigatetoward the targeted tissue site 150, the operator should manipulate themaster input device 12 forward, to the right, and down. The right viewwill provide valued navigation information, but will not be asinstinctive from a “driving” perspective.

To illustrate: if the operator wishes to insert the catheter tip towardthe targeted tissue site 150 watching only the rightmost view 144without the master input device 12 coordinate system synchronized withsuch view, the operator would have to remember that pushing straightahead on the master input device will make the distal tip representation148 move to the right on the rightmost display 144. Should the operatordecide to toggle the system to use the rightmost view 144 as the primarynavigation view, the coordinate system of the master input device 12 isthen synchronized with that of the rightmost view 144, enabling theoperator to move the catheter tip 148 closer to the desired targetedtissue location 150 by manipulating the master input device 12 down andto the right. The synchronization of coordinate systems may be conductedusing fairly conventional mathematic relationships which are describedin detail in the aforementioned applications incorporated by reference.

Referring back to embodiment of FIG. 13, the master computer 126 alsocomprises software and hardware interfaces to operator control stationbuttons, switches, and other input devices which may be utilized, forexample, to “freeze” the system by functionally disengaging the masterinput device as a controls input, or provide toggling between variousscaling ratios desired by the operator for manipulated inputs at themaster input device 12. The master computer 126 has two separatefunctional connections with the control and instrument driver computer128: one connection 132 for passing controls and visualization relatedcommands, such as desired XYZ (in the catheter coordinate system)commands, and one connection 134 for passing safety signal commands.Similarly, the control and instrument driver computer 128 has twoseparate functional connections with the instrument and instrumentdriver hardware 130: one connection 136 for passing control andvisualization related commands such as required-torque-related voltagesto the amplifiers to drive the motors and encoders, and one connection138 for passing safety signal commands. Also shown in the signal flowoverview of FIG. 13 is a pathway 140 between the physical instrument andinstrument driver hardware 130 back to the master computer 126 to depicta closed loop system embodiment wherein instrument localizationtechnology is utilized to determine the actual position of theinstrument to minimize navigation and control error.

II. Tension Sensing.

As discussed with reference to FIGS. 6-7, the robotic system 10 includesan instrument driver (or drive assembly) 16 with sleeve receptacles 90for turning the respective shafts 82 at the sterile adaptor 41, which inturn, rotates the respective pulley assemblies 80 at the splayer 61/62.In some embodiments, the robotic system 10 may further include a sensorfor sensing a characteristic that corresponds with an amount of force ortorque being applied to turn the sleeve receptacles 90. FIG. 15illustrates some components of the robotic system 10 that includestension sensing capability in accordance with some embodiments. As shownin the figure, the instrument driver 16 includes the sleeve receptacles90, which are actuatable elements that are actuated by respective motors200. The instrument driver 16 also includes sensors 202 coupled to therespective motors 200. Each sensor 202 is configured to sense acharacteristic that corresponds with an amount of force or torque beingapplied to the actuatable element 90. The sensor 202 is illustratedschematically as being coupled to the motor 200. In some embodiments,the sensor 202 may be located internally inside a motor. In otherembodiments, the sensor 202 may be secured to an exterior of a motor. Inother embodiments, the sensor 202 may be attached to a component that iscoupled to the motor. For example, in some embodiments, the motor 200may be mounted to a ring structure (like the ring structure 300 shown inFIG. 19) that is attached to the instrument driver 16. In such cases,the sensor 202 may be attached to the ring structure, and the sensor 202may be considered as being coupled to the motor 200 (indirectly, in thisexample).

The robotic system 10 also includes the sterile adaptor 41, which has abase 220 with a plurality of openings 224 for housing respective rotarymembers 82. In the illustrated embodiments, the rotary members 82 areshafts configured for detachably coupling to respective sleevereceptacles 90. In particular, each rotary member 82 has a first end 210for insertion into the sleeve receptacle 90, a second end 212, and abody 214 extending between the first and second ends 210, 212. Thesterile adaptor 41 also includes a cover 222 that is coupled to the base220, and a flexible sheet (membrane) 226 for providing a sterile barrierso that after the splayer assembly 61/62 is used, the sterile adaptor 41and the splayer assembly 61/62 may be discarded, while leaving theinstrument driver 16 sterile.

The robotic system 10 also includes the splayer 61/62, which includes abase 78 with a plurality of openings 230 for housing respective pulleyassemblies 80, and a cover 72 for coupling to the base 78. When thecover 72 is coupled to the base 78, it covers the pulley assemblies 80.The splayer 61/62 also includes an elongate member 61 a/62 a coupled tothe base 78 (e.g., either directly to the base 78, or indirectly to thebase 78 through the cover 72). The elongate member 61 a/62 a may be acatheter, a sheath, or any elongate instrument having a lumen extendingtherethrough. The robotic system 10 also includes a plurality ofsteering wires 204 disposed in the elongate member 61 a/62 a. Eachsteering wire 204 has a distal end coupled to a distal end of theelongate member, and a proximal end coupled to one of the pulleyassemblies 80. During use, the pulley assembly may be rotated to applytension to the steering wire 204 to thereby apply tension to thesteering wire 204, which in turn, causes the distal end of the elongatemember 61 a/62 a to bend. Although two pulley assemblies 80 are shown,it should be understood that in other embodiments, the splayer 61/62 mayhave more than two pulley assemblies 80 (e.g., four pulley assemblies80), with respective steering wires 204 connected thereto. Also, inother embodiments, the splayer 61/62 may have only one pulley assembly80, and the elongate member 61 a/62 a may have only one steering wire204 connected to the pulley assembly 80.

As shown in the figure, the actuatable element 90 is configured to turnthe pulley assembly 80 indirectly through the rotary member 82 at thesterile adaptor 41 to thereby apply tension to the steering wire 204 atthe catheter 61 a/sheath 62 a. The sensor 202 is configured to sense acharacteristic that corresponds with an amount of force being applied tothe actuatable element 90. By means of non-limiting examples, thecharacteristic may be an actual force, a torque (which is force timesdistance), a strain, a stress, an acceleration, etc. The sensedcharacteristic may be used to correlate an amount of tension beingapplied to the steering wire 204. In some embodiments, the sensedcharacteristic may be transmitted from the sensor 202 to the userinterface 2, and the value of the sensed characteristic may be displayedon a screen for presentation to a user. Also, in some embodiments, thesensed characteristic may be transmitted from the sensor 202 in a formof a signal to a processor, which processes the signal, and controls anamount of torque/force being applied to the motor 200 in response to theprocessed signal.

In some embodiments, in order to accurately correlate the sensedcharacteristic by the sensor 202 with an amount of tension being appliedat the steering wire 204, it may be desirable to minimize, or at leastreduce an amount of friction between the shaft 82 and the base 220 atthe sterile adaptor 41. In the illustrated embodiments, the sterileadaptor 41 includes an interface between each rotary member 82 and thebase 220 for reducing an amount of friction therebetween (i.e., betweenthe shaft body 214 of the rotary member 82 and the wall in the opening224 defined by the base 220). As shown in the figure, each rotary member82 includes a flange 240 disposed circumferentially around the shaftbody 214, and a plurality of slots 242 at the flange 240. Two slots 242are shown, which are defined by a partition 244 extending round theshaft body 214 of the rotary member 82. The partition 244 may have aring configuration. For example, the partition 244 may have a continuousring structure, or alternatively, a plurality of structures that form aring configuration. Each slot 242 has a ring configuration that extendsaround the shaft body 214 of the rotary member 82. Also, as shown in thefigure, the base 220 includes a protrusion 246 next to (e.g., within 5cm or less from) the opening 224. The protrusion 246 has a ringconfiguration around the opening 224, and extends into a slot 242. Forexample, the protrusion 246 may have a continuous ring structure, oralternatively, may have a plurality of structures that form into a ringconfiguration. Although one protrusion 246 is shown in the example, inother embodiments, the sterile adaptor 41 may include a plurality ofprotrusions 246 that extend into respective ones of the slots 242 at theflange 240. Also, in other embodiments, the flange 240 of the rotarymember 82 may include more than two slots 242, or less than two slots242 (e.g., only one slot 242).

In the illustrated embodiments, the cross sectional dimension of theshaft body 214 is less than the cross sectional dimension of the opening224 (e.g., by 3 mm, and more preferably by 2 mm, and even morepreferably by 1 mm or less). The partition(s) 244 at the flange 240 andthe protrusion(s) 246 at the base 220 cooperate with each other (e.g.,engage with each other) to prevent the shaft 214 from touching thesurrounding wall at the opening 224. Accordingly, the shaft body 214essentially “floats” within the space defined by the opening 224. In theillustrated embodiments, the partition 244 abuts against the protrusion246 while the shaft body 214 is maintained within the opening 224 sothat it is spaced away from the wall of the opening 224. In otherembodiments, the partition 244 may not abut against the protrusion 246.Instead, there may be a small gap between the partition 244 and theprotrusion 246 to reduce friction between the partition 244 and theprotrusion 246. The gap may be large enough to allow some movement ofthe shaft body 214 relative to the base 220, while small enough toprevent the shaft body 214 from touching the wall at the opening 224.

In some embodiments, to further provide a frictionless interface, thepartition(s) 244 and/or the protrusion(s) 246 may be coated with ahydrophobic material to allow fluid to glide easily along the surfacesof these components. Also, in some embodiments, a lubricant, such asoil, may be applied to the surface of the partition(s) 244 and/or theprotrusion(s) 246.

During use, the sterile adaptor 41 is detachably coupled to theinstrument driver 16. Such may be accomplished by inserting the firstends 210 of the respective rotary members 82 into respective openings atthe acutatable elements 90 (like that shown in FIG. 7E). The membrane226 provides a barrier to prevent the instrument driver 16 from beingcontaminated during a medical procedure. Also, during use, the splayer61 is detachably coupled to the sterile adaptor 41. Such may beaccomplished by inserting the second ends 212 of the respective rotarymembers 82 into respective openings at the end of the rotary members 80(like that shown in FIG. 7D).

The same setup may be performed for the splayer 62. In particular,during use, another sterile adaptor 41 is detachably coupled to theinstrument driver 16. Such may be accomplished by inserting the firstends 210 of the respective rotary members 82 into respective openings atthe acutatable elements 90 (like that shown in FIG. 7E). Also, thesplayer 62 is detachably coupled to the sterile adaptor 41. Such may beaccomplished by inserting the second ends 212 of the respective rotarymembers 82 into respective openings at the end of the rotary members 80(like that shown in FIG. 7D).

After the splayers 61, 62 are mounted to respective sterile adaptors 41,and after the sterile adaptors 41 are mounted to the instrument driver16, the robotic system 10 may then be used to perform a medicalprocedure. For example, in some embodiments, the splayer 61 and/orsplayer 62 may be controlled to position the catheter 61 a and/or thesheath 62 a at desired position(s) within the patient. Once the catheter61 a and/or the sheath 62 a have been desirably positioned, the catheter61 a and/or the sheath 62 a may then be used to deliver an instrument(e.g., an ablation device) or a substance (e.g., occlusive device, drug,etc.) to treat the patient.

Various techniques may be employed to move the catheter 61 a and/or thesheath 62 a to thereby place these instruments at desired positions(s)in the patient. In some embodiments, the instrument driver 16 may beconfigured to translate the splayer 61 to thereby translate the catheter61 a in an axial direction. Also, the instrument driver 16 may beconfigured to translate the splayer 62 to thereby translate the sheath62 a in an axial direction. Thus, by moving the splayer 61 and/orsplayer 62, the instrument driver 16 may advance or retract the catheter61 a relative to the sheath 62 a, and vice versa. Also, if the movementsof the splayers 61, 62 are synchronized, both the catheter 61 a and thesheath 62 a may be moved by the same amount in some embodiments. In someembodiments, the translation of the splayer 61 and/or the splayer 62 maybe performed by the instrument driver 16 in response to a command signalreceived from the user interface. For example, in some embodiments, theinstrument driver 16 may be configured to receive a command signal inputfrom a user at the user interface, and generate a control signal inresponse to the command signal to move one or both of the splayers 61,62.

Also, in some embodiments, the instrument driver 16 may be configured tobend a distal end of the catheter 61 a, a distal end of the sheath 62 a,or both. For example, in some embodiments, the instrument driver 16 mayactuate one or more motors at the instrument driver 16 to turn one ormore respective actuatable elements 90, thereby turning one or morerespective rotary members 80 at the splayer 61 indirectly through theone or more respective rotary members 82 at the sterile adaptor 41. Theturning of the one or more rotary members 80 at the splayer 61 appliestension to one or more respective steering wires to thereby bend thecatheter 61 a towards a certain direction.

Similarly, in some embodiments, the instrument driver 16 may actuate oneor more motors at the instrument driver 16 to turn one or morerespective actuatable elements 90, thereby turning one or morerespective rotary members 80 at the splayer 62 indirectly through theone or more respective rotary members 82 at the sterile adaptor 41. Theturning of the one or more rotary members 80 at the splayer 62 appliestension to one or more respective steering wires to thereby bend thesheath 62 a towards a certain direction.

In some embodiments, as the rotary member 80 is being turned to applytension to the steering wire 204, the sensor 202 senses a characteristicthat correlates with an amount of force or torque being applied by theactuatable element 90. For example, in some embodiments, the sensor 202may be a torque sensor configured to measure an amount of torque beingapplied to the actuatable element 90. The measured torque may be dividedby a moment arm (e.g., a radius of the actuatable element 90) to derivea force value. In some embodiments, the force value may correlate withan amount of tension being applied to the steering wire 204. Forexample, in some cases, the force value may be considered to be theamount of tension being applied to the steering wire 204. In otherembodiments, the sensor 202 may be a force sensor configured to measurea force vector that is in opposite direction as the tension force at thesteering wire 204. Because of the frictionless interface at the sterileadaptor 41, the force sensed by the sensor 202 may be substantiallyequal to (e.g., at least 80%, and more preferably at least 90%, and evenmore preferably at least 99% of) the amount of tension at the steeringwire 204.

In some embodiments, the sensed characteristic by the sensor 202 may beused in a process to steer the distal end of the catheter 61 a/sheath 62a so that the distal end achieves a desired amount of bending. Forexample, in some embodiments, in a method of steering the distal end ofthe catheter 61 a/sheath 62 a (elongate member), an amount of bending tobe achieved by the distal end of the elongate member may first bedetermined. Such may be accomplished by a user of the system 10.Alternatively, such may be accomplished automatically by a processorbased on an anatomy of the patient, and the location of the elongatemember 61 a/62 a. Next, an amount of tension to be applied to thesteering wire 204 located within the elongate member 61 a/62 a may bedetermined based on the amount of bending that is desired to beachieved. In general, the more tension is being applied to the steeringwire 204, the more the amount of bending will be achieved at the distalend of the elongate member 61 a/62 a. In some embodiments, the amount oftension may be calculated automatically by the processor based onstructural properties (e.g., bending stiffness) of the elongate member61 a/62 a. Next, the instrument driver 16 actuates the actuatableelement 90 to apply a torque to turn the rotary member 80 that isdetachably coupled (directly or indirectly through element 82) to theactuatable element 90. The application of the torque by the actuatableelement 90 causes tension to be applied to the steering wire 204. Whilethe actuatable element 90 is being actuated, the sensor 202 senses acharacteristic that corresponds with an amount of force or torque beingapplied by the actuatable element 90 to turn the rotary member 80. Inthe illustrated embodiments, the act of using the actuatable element 90to apply the torque comprises increasing the amount of force or torquebeing applied by the actuatable element 90 until the sensedcharacteristic by the sensor 202 indicates that the determined amount oftension at the steering wire 204 has been achieved. The above techniquefor bending the elongate member 61 a/62 a is advantageous because itobviates the need to determine how much axial movement (e.g., due toaxial strain of the steering wire 204, and relative movement between thesteering wire 204 and the elongate member 61 a/62 a) needs to beachieved by the steering wire 204 in order to achieve a certain desiredamount of bending. In particular, the above technique involving use ofthe sensor 202 is advantageous over another technique of achieving adesired amount of bending, which involve determining how much tension isneeded at the steering wire 204, and then determining a required amountof axial movement by the steering wire 204 that corresponds with thedetermined tension. Then the system monitors an amount of axial movementby the steering wire 204 until the required amount of axial movement bythe steering wire 204 is achieved. However, calculating the requiredamount of axial movement needs to be achieved by the steering wire basedon the required tension may be difficult, computational intensive, andmay not be accurate.

Also as illustrated in the above embodiments, the frictionless interfaceat the sterile adaptor 41 is advantageous because it significantlyremove all or most of the friction between the rotary member 82 and itssurrounding wall in the opening 224. Thus, the frictionless interface atthe sterile adaptor 41 is preferred over rubber seal, and the roboticsystem 10 does not include any rubber seal between the rotary member 82and the base 220 of the sterile adaptor 41.

In the above embodiments, the rotary member 80 at the splayer 61/62 hasbeen described as having an opening at one end of the rotary member 80for receiving the second end 212 of the rotary member 82 at the sterileadaptor 41. In other embodiments, the configuration of the coupling maybe reversed. For example, in other embodiments, the rotary member 80 atthe splayer 61/62 may have an end for insertion into an opening at thesecond end 212 of the rotary member 82 at the sterile adaptor 41 (FIG.16).

Also, in the above embodiments, the first end 210 of the rotary member82 at the sterile adaptor 41 has been described as being inserted intoan opening at the actuatable element 90 at the instrument driver 16. Inother embodiments, the configuration of the coupling may be reversed.For example, in other embodiments, the first end 210 of the rotarymember 82 at the sterile adaptor 41 may have an opening for receiving anend of the actuatable element 90 at the instrument driver 16 (FIG. 17).Furthermore, in other embodiments, the second end 212 of the rotarymember 82 in the embodiments of FIG. 17 may be configured for insertioninto an opening at the end of the rotary member 80 (like that shown inFIG. 15).

In the above embodiments, the frictionless interface at the sterileadaptor 41 includes two slots 242 and a protrusion 246 inserted into oneof the slots 242. In other embodiments, the frictionless interface mayinclude an additional protrusion 246 extending into the second slot 242.Also, in further embodiments, the frictionless interface may includeonly one slot 242 (FIG. 18).

As discussed, the sensor 202 is coupled to the motor 200, eitherdirectly or indirectly. Various techniques may be employed for couplingthe sensor 202 to the motor 200. In some embodiments, the sensor 202 maybe a strain gauge mounted to an output shaft. In other embodiments, thesensor 202 may be a torque sensor mounted in series with the outputshaft.

In further embodiments, the motor 200 (with optional gearbox) may bemounted to the instrument driver 16 (e.g., to a chassis of theinstrument driver) through a mounting structure 300 (FIG. 19). In suchcases, the sensor 202 may be attached to the mounting structure 300.Such configuration is advantageous because it allows torque to bemeasured at the output shaft by measuring the reaction forces from theentire gear train. This is because at static equilibrium, the measuredreaction torque may be equal to the output shaft torque. The mountingstructure 300 has a ring configuration in some embodiments. In otherembodiments, the mounting structure 300 may have other configurations.Also, in some embodiments, the mounting structure 300 may be consideredto be a part of the sensor 202. The sensor 202 (and optionally with themounting structure 300) may be a torque sensor, a hinge or flexure basedstructure with integrated load cell(s) or strain gauge(s), or a straingauge mounted to an otherwise rigid mounting structure.

In some cases, the sensor 202 may pick up inertial forces from theacceleration and deceleration of the motor 200. Options for minimizingthis contamination include (1) low-pass filtering the measured signal,(2) using only data collected when the motor 200 is stationary or movingat an approximately constant velocity, and/or (3) modeling the inertialeffects of the motor 200, and compensating the measured signal basedupon a measured acceleration by an encoder at the motor 200 and/or motorback-EMF.

In other embodiments, by mounting the axis of the motor 200 at 90°relative to the axis of the output shaft, the inertia forces due toacceleration and deceleration of the motor 200 will be decoupled fromthe measured reaction torque (FIG. 20). As shown in the figure therobotic system 10 may optionally further include a gear box 310 fortransmitting torque from the motor 200 to the output shaft that isaxially aligned with the actuatable element 90. In such cases, theacceleration of the output shaft, pulley, etc., may still contaminatethe measurement of wire tension, but these contributions will berelatively small compared to the acceleration of the motor rotor,especially because of the effects of gear reduction between motor andoutput shaft. The sensor 202 (and optionally with the mounting structure300) may be a torque sensor, a hinge or flexure based structure withintegrated load cell(s) or strain gauge(s), or a strain gauge mounted toan otherwise rigid mounting structure.

In further embodiments, the instrument driver 16 may include adifferential gearbox 320 mechanically coupled to the motor 200 (FIG.21). The gearbox 320 is configured to turn a first output shaft 322 thatis coupled to the actuatable element 90, while a second output shaft 324extending from the gearbox 320 is fixed to the instrument driver 16(e.g., to a chassis of the instrument driver 16). In some embodiments,the second output shaft 324 may be fixed to the instrument driver 16through the sensor 202 (see option A in figure), which may be a torquesensing element in some embodiments. Alternatively, the second outputshaft 324 may be fixed to the instrument driver 16 without using thesensor 202, in which cases, the sensor 202 (which may be a strain gaugein some embodiments) may be secured to the second output shaft 324 (seeoption B in figure). The gearbox 320 is advantageous because it allowsthe sensor 202 to be coupled to a component that experiences torque fromthe gearbox 320, but does not spin (which is beneficial because itobviates the need to implement complicated signal connection, such as aslip connection, that may otherwise be needed if the sensor 202 iscoupled to a spinning shaft). In some embodiments, the gearbox 320 maybe similar to that used in transferring power to both wheels of anautomobile while allowing them to rotate at different speeds. In somecases, the difference between the torque in the upper and lower outputshafts 322, 324 may be due to inefficiencies of the differential gearbox320. In such cases, by maximizing the efficiency of the differentialgearbox 320, the sensor 202 may provide a good estimate of the pullwiretension without having to deal with routing signal connections to asensor that is moving. Also, in some embodiments, the configuration ofthe embodiments shown in FIG. 21 may be simplified by incorporating thesecondary (fixed) output shaft 324 and the sensor 202 entirely within ahousing of the differential gearbox 320. This may provide for a compactgearbox with integrated output shaft torque sensing and no limitationson output shaft motion.

III. Driving Modes

As discussed, the system 10 may be configured to move the sheath 62 adistally or proximally, move the catheter 61 a distally or proximally,and to move the elongate member 26 distally or proximally. In somecases, the movement of the sheath 62 a may be relative to the catheter61 a, while the catheter 61 a remains stationary. In other cases, themovement of the catheter 61 a may be relative to the sheath 62 a whilethe sheath 62 a remains stationary. Also, in other cases, the sheath 62a and the catheter 61 a may be moved together as a unit. The elongatemember 26 may be moved relative to the sheath 62 a and/or the catheter61 a. Alternatively, the elongate member 26 may be moved together withthe sheath 62 a and/or the catheter 61 a.

In some embodiments, the workstation 2 is configured to provide some orall of the following commanded motions (driving modes) for allowing thephysician to choose. In some embodiments, each of the driving modes mayhave a corresponding button at the workstation 2 and/or the bedsidecontrol 402.

Elongate member Insert—When this button/command is selected, themanipulator 24 inserts the elongate member 26 at a constant velocity.

Elongate member Roll—When this button/command is selected, themanipulator 24 rolls the elongate member 26 at a constant angularvelocity

Elongate member Size—When the size or gauge of the elongate member 26 isinputted into through the user interface, the system will automaticallyalter roll and insert actuation at the proximal end of the elongatemember 26 accordingly to achieve desired commanded results. In oneimplementation, when a user inputs the elongate member's size, thesystem automatically changes its kinematic model for driving thatelongate member 26. So if the user commands the elongate member 26 tomove to a certain position, the system will calculate, based on thekinematic model, roll and insert commands, which may be different fordifferent elongate member sizes (e.g., elongate members 26 withdifferent diameters). By inputting the elongate member's size, thesystem knows which kinematic model to use to perform the calculation.Such feature is beneficial because different sized elongate members 26behave differently.

Leader/Sheath Select—When this button/command is selected, it allows theuser to select which device (e.g., catheter 61 a, sheath 62 a, elongatemember 26, or any combination of the foregoing) is active.

Leader/Sheath Insert/Retract—When this button/command is selected, theinstrument driver assembly inserts or retracts the catheter 61 a/sheath62 a while holding the elongate member 26 and any non-active devicefixed relative to the patient. When this motion causes the protrudingsection of the catheter 61 a to approach zero (due to insertion of thesheath 62 a or retraction of the catheter 61 a), the systemautomatically relaxes the catheter 61 a as part of the motion.

Leader/Sheath Bend—When this button/command is selected, the instrumentdriver assembly bends the articulating portion of the catheter 61a/sheath 62 a within its currently commanded articulation plane.

Leader/Sheath Roll—When this button/command is selected, the instrumentdriver assembly uses the pullwires to “sweep” the articulation plane ofthe device (catheter 61 a and/or sheath 62 a) around in a circle throughbending action of the device. Thus, this mode of operation does notresult in a true “roll” of the device in that the shaft of the devicedoes not roll. In other embodiments, the shaft of the device may beconfigured to rotate to result in a true roll. Thus, as used in thisspecification, the term “roll” may refer to an artificial roll createdby seeping a bent section, or may refer to a true roll created byrotating the device.

Leader/Sheath Relax—When this button/command is selected, the instrumentdriver assembly gradually releases tension off of the pullwires on thecatheter 61 a/sheath 62 a. If in free space, this results in the devicereturning to a straight configuration. If constrained in an anatomy,this results in relaxing the device such that it can most easily conformto the anatomy.

Elongate Member Lock—When this button/command is selected, the elongatemember 26 position is locked to the catheter 61 a position. As theleader is articulated or inserted, the elongate member 26 moves with thecatheter 61 a as one unit.

System Advance/Retract—When this button/command is selected, theinstrument driver assembly advances/retracts the catheter 61 a andsheath 62 a together as one unit. The elongate member 26 is controlledto remain fixed relative to the patient.

Autoretract—When this button/command is selected, the instrument driverassembly starts by relaxing and retracting the catheter 61 a into thesheath 62 a, and then continues by relaxing and retracting the sheath 62a with the catheter 61 a inside it. The elongate member 26 is controlledto remain fixed relative to the patient.

Initialize Catheter—When this button/command is selected, the systemconfirms that the catheter 61 a and/or the sheath 62 a has been properlyinstalled on the instrument driver assembly, and initiatespretensioning. Pretensioning is a process used to find offsets for eachpullwire to account for manufacturing tolerances and the initial shapeof the shaft of the catheter 61 a and/or the sheath 62 a.

Leader/Sheath Re-calibration—When this button/command is selected, theinstrument driver assembly re-pretensions the catheter 61 a and/or thesheath 62 a in its current position. This gives the system theopportunity to find new pretension offsets for each pullwire and canimprove catheter driving in situations where the proximal shaft of thecatheter 61 a has been placed into a significant bend. It is activatedby holding a relax button down for several seconds which ensures thatthe device is fully de-articulated. Alternatively the re-calibration maybe activated without holding down the relax button to de-articulate thedevice.

Leader Relax Remove—When this button/command is selected, the instrumentdriver assembly initiates a catheter removal sequence where the catheter61 a is fully retracted into the sheath 62 a, all tension is releasedfrom the pullwires, and the splayer shafts (at the drivable assembly 61and/or drivable assembly 62) are driven back to their original installpositions so that the catheter 61 a can be reinstalled at a later time.

Leader Yank Remove—When this button/command is selected, the instrumentdriver assembly initiates a catheter removal sequence where the catheter61 a is removed manually.

Emergency Stop—When this button/command is selected, the instrumentdriver assembly initiates a gradual (e.g., 3 second) relaxation of boththe catheter 61 a and the sheath 62 a. The components (e.g., amplifier)for operating the catheter 61 a, elongate member 26, or another deviceare placed into a “safe-idle” mode which guarantees that no power isavailable to the motors that drive these elements, thereby bringing themrapidly to a stop, and allowing them to be manually back-driven by theuser. Upon release of the emergency stop button, the system ensures thatthe catheter 61 a is still in its allowable workspace and then returnsto a normal driving state.

Segment control: In some embodiments, the workstation 2 allows a user toselect individual segment(s) of a multi-segment catheters (such as thecombination of the catheter 61 a and the sheath 62 a), and control eachone. The advantage of controlling the catheter in this way is that itallows for many options of how to control the movement of the catheter,which may result in the most desirable catheter performance. To executethis method of catheter steering, the user selects a segment of thecatheter to control. Each segment may be telescoping or non-telescoping.The user may then control the selected segment by bending and insertingit using the workstation 2 to control the position of the end point ofthe catheter. Other segment(s) of the catheter will either maintaintheir previous position (if it is proximal of the selected section) ormaintain its previous configuration with respect to the selected section(if it is distal of that section) (FIG. 22A).

Follow mode: In some embodiments, the workstation 2 allows the user tocontrol any telescoping section while the more proximal section(s)follows behind automatically. This has the advantage of allowing theuser to focus mostly on the movement of a section of interest while itremains supported proximally. To execute this method of cathetersteering, the user first selects a telescoping section of the elongateinstrument (e.g., catheter 61 a and sheath 62 a) to control. Thissection is then controlled using the workstation 2 to prescribe alocation of the endpoint of the segment. Any segment(s) distal of thesection of interest will maintain their previous configuration withrespect to that section. When the button on the workstation 2 isreleased, any segment(s) proximal of the section of interest will followthe path of the selected section as closely as possible until apredefined amount of the selected section remains (FIG. 22B). As analternative to this driving mode, the segment(s) of the elongateinstrument which is proximal of the section of interest could followalong as that segment is moved instead of waiting for the button to bereleased. Furthermore, with either of these automatic follow options,the system may optionally be configured to re-pretension the sectionsthat have been driven out and re-align the sections that are proximal ofthe driven section.

Follow mode may be desirable to use to bring the more proximal segmentsof the elongate instrument towards the tip to provide additional supportto the distal segment. In cases where there are three or morecontrollable sections of the elongate instrument, there are severaloptions for how to execute a “follow” command. Consider the example inFIG. 22D where the distal segment (which may be a guidewire or asteerable instrument in some embodiments) has been driven out as shownin frame 1. The “follow” command could be executed by articulatingand/or inserting only the middle segment (which may be the catheter 61 ain some embodiments) of the elongate instrument as shown in frame 2. The“follow” command could be executed by articulating and/or inserting onlythe most proximal segment (which may be the sheath 62 a in someembodiments) of the elongate instrument as shown in frame 3. The“follow” command could also be executed by coordinating the articulationand/or insertion of multiple proximal segments of the elongateinstrument as shown in frame 4. Combining the motion of multiplesections has several potential advantages. First, it increases the totaldegrees-of-freedom available to the algorithm that tries to fit theshape of the following section(s) to the existing shape of the segmentbeing followed. Also, in comparison to following each segmentsequentially, a multi-segment follow mode simplifies and/or speeds upthe workflow. In addition, multi-segment increases the distance that canbe followed compared to when only one proximal segment is used to followthe distal segment.

Mix-and-match mode: In some embodiments, the workstation 2 allows theuser to have the option of mixing and matching between articulating andinserting various sections of a catheter. For example, consider theillustration in FIG. 22C, and assuming that the distal most section ofthe elongate instrument is the “active” segment. If the user commands amotion of the tip of the elongate instrument as indicated by the arrowin Frame 1, there are several options available for how to achieve thiscommand: (1) Articulate and extend the “active” segment, which isillustrated in frame 3 and is likely considered the normal or expectedbehavior; (2) Articulate the active distal most segment and insert oneof the other proximal segments, as illustrated in frames 2 and 4; (3)Articulate the active distal most segment and combine inserting motionof some or all of the segments, as illustrated in frame 5.

There are multiple potential reasons why the user might want to choosesome of these options. First, by “borrowing” insert motion from othersegments, some of the segments could be constructed with fixed lengths.This reduces the need for segments to telescope inside of each other,and therefore reduces the overall wall thickness. It also reduces thenumber of insertion degrees-of-freedom needed. Also, by combining theinsert motion from several segments, the effective insertrange-of-motion for an individual segment can be maximized. In aconstrained space such as the vasculature, the operator may likely beinterested in “steering” the most distal section while having as mucheffective insertion range as possible. It would simplify and speed upthe workflow to not have to stop and follow with the other segments.

In other embodiments, the “follow” mode may be carried out using arobotic system that includes a flexible elongated member (e.g., aguidewire), a first member (e.g., the catheter 61 a) disposed around theflexible elongated member, and a second member (e.g., the sheath 62 a)disposed around the first member. The flexible elongated member may havea preformed (e.g., pre-bent) configuration. In some embodiments, theflexible elongated member may be positioned inside a body. Such may beaccomplished using a drive mechanism that is configured to position(e.g., advance, retract, rotate, etc.) the flexible elongated member. Inone example, the positioning of the flexible elongated member comprisesadvancing the flexible elongated member so that its distal end passesthrough an opening in the body.

Next, the first member is relaxed so that it has sufficient flexibilitythat will allow the first member to be guided by the flexible elongatedmember (that is relatively more rigid than the relaxed first member). Insome embodiments, the relaxing of the first member may be accomplishedby releasing tension in wires that are inside the first member, whereinthe wires are configured to bend the first member or to maintain thefirst member in a bent configuration. After the first member is relaxed,the first member may then be advanced distally relative to the flexibleelongated member. The flexible elongated member, while being flexible,has sufficient rigidity to guide the relaxed first member as the firstmember is advanced over it. The first member may be advanced until itsdistal end also passes through the opening in the body.

In some embodiments, the second member may also be relaxed so that ithas sufficient flexibility that will allow the second member to beguided by the flexible elongated member (that is relatively more rigidthan the relaxed second member), and/or by the first member. In someembodiments, the relaxing of the second member may be accomplished byreleasing tension in wires that are inside the second member, whereinthe wires are configured to bend the second member or to maintain thesecond member in a bent configuration. After the second member isrelaxed, the second member may then be advanced distally relative to theflexible elongated member. The flexible elongated member, while beingflexible, has sufficient rigidity to guide the relaxed second member asthe second member is advanced over it. The second member may be advanceduntil its distal end also passes through the opening in the body. Inother embodiments, instead of advancing the second member after thefirst member, both the first member and the second member may beadvanced simultaneously (e.g., using a drive mechanism) so that theymove together as a unit. In further embodiments, the acts of advancingthe flexible elongated member, the first member, and the second membermay be repeated until a distal end of the flexible elongated member, thefirst member, or the second member has passed through an opening in abody.

In the above embodiments, tension in pull wires in the second elongatedmember is released to make it more flexible than the first elongatedmember, and the second elongated member is then advanced over the firstelongated member while allowing the first elongated member to guide thesecond elongated member. In other embodiments, the tension in the pullwires in the first elongated member may be released to make it moreflexible than the second elongated member. In such cases, the moreflexible first elongated member may then be advanced inside the morerigid second elongated member, thereby allowing the shape of the secondelongated member to guide the advancement of the first elongated member.In either case, the more rigid elongated member may be locked into shapeby maintaining the tension in the pull wires.

In some of the embodiments described herein, the flexible elongatedmember may be a guidewire, wherein the guidewire may have a circularcross section, or any of other cross-sectional shapes. Also, in otherembodiments, the guidewire may have a tubular configuration. In stillother embodiments, instead of a guidewire, the flexible elongated membermay be the member 26. In further embodiments, the robotic system mayfurther include a mechanism for controlling and/or maintaining thepreformed configuration of the guidewire. In some embodiments, suchmechanism may include one or more steering wires coupled to a distal endof the guidewire. In other embodiments, such mechanism may be thecatheter 61 a, the sheath 62 a, or both. In particular, one or both ofthe catheter 61 a and the sheath 62 a may be stiffened (e.g., byapplying tension to one or more wires inside the catheter 61 a and/orthe sheath 62 a). The stiffened catheter 61 a and/or the sheath 62 a maythen be used to provide support for the guidewire.

Also, in some of the embodiments described herein, any movement of theelongate member 26, the catheter 61 a, and/or the sheath 62 a may beaccomplished robotically using a drive assembly. In some embodiments,the drive assembly is configured to receive a control signal from aprocessor, and actuate one or more driveable elements to move theelongate member 26, the catheter 61 a, and/or the sheath 62 a.

It should be noted that the driving modes for the system are not limitedto the examples discussed, and that the system may provide other drivingmodes in other embodiments.

IV. Treatment Methods

FIGS. 23A-23F illustrate a method of treating tissue using the roboticsystem 10 in accordance with some embodiments. As an example, the methodwill be described with reference to treating liver tissue. However, itshould be understood that the system 10 may be used to treat other typesof tissue.

First, the robotic system 10 is setup by placing the catheter 61 intothe lumen of the sheath 62, and by placing the elongate member 26 intothe lumen of the catheter 61. Next, an incision is then made at apatient's skin, and the distal end of the catheter 61 is then insertedinto the patient through the incision. In particular, the distal end ofthe catheter 61 is placed inside a vessel 2000 (e.g., a vein or anartery) of the patient. In some embodiments, the liver may be accessedfrom the femoral vein or femoral artery from either groin. In otherembodiments, the liver may be accessed from the right sub-clavin in veinor the right jugular vein. In some embodiments, the initial insertion ofthe catheter 61 into the patient may be performed manually. In otherembodiments, the initial insertion of the catheter 61 may be performedrobotically using the system 10. In such cases, the user may enter acommand at the workstation 2, which then generates a user signal inresponse thereto. The user signal is transmitted to a controller, whichthen generates a control signal in response to the user signal. Thecontrol signal is transmitted to the driver to drive the catheter 61 sothat it advances distally into the patient. In some embodiments, whilethe catheter 61 is being inserted into the patient, the distal end 2300of the elongate member 26 may be housed within the lumen of the catheter61. In other embodiments, the distal end 2300 of the elongate member 26may extend out of the lumen of the catheter 61 (which the flexiblesection 320 of the elongate member 26 is housed within the lumen of thecatheter 61) as the catheter 61 is being inserted. In such cases, thesharp distal tip of the elongate member 26 may facilitate insertionthrough the patient's skin. In other embodiments, the tip of theelongate member 26 may not be sharp enough, or the distal section of theelongate member 26 may not be stiff enough, to puncture the patient'sskin. In such cases, a separate tool may be used to create an incisionat the patient's skin first, as discussed.

In some embodiments, after the catheter 61 a is placed inside thepatient, the sheath 62 a may be advanced distally over the catheter 61a. Alternatively, both the catheter 61 a and the sheath 62 a may beadvanced simultaneously to enter into the patient.

Once the catheter 61 a and the sheath 62 a are inserted into thepatient, they can be driven to advance through the vasculature of thepatient. At sections of the vessel 2000 that are relatively straight,both the catheter 61 a and the sheath 62 a may be driven so that theymove as one unit. Occasionally, the catheter 61 a and/or the sheath 62 amay reach a section of the vessel 2000 that has a bend (e.g., a sharpbend). In such cases, the catheter 61 a and the sheath 62 a may bedriven in a telescopic manner to advance past the bend.

FIGS. 23A-23B illustrate such telescopic technique for advancing thesheath 62 a and the catheter 61 a over a bend 2002 along a length of thevessel 2000. In this technique, the catheter 61 a is positioned with itsdistal articulation section traversing the bend 2002 and it is locked inthis position (FIG. 23A). Next, the sheath 62 a is advanced over thecatheter 61 a (FIG. 23B), and the catheter 61 a acts as a rail held in afixed shape for the sheath 62 a to glide over. As the sheath 62 a isadvanced further, sections with higher bending stiffness on the sheath62 a will pass over the articulated section of the catheter 61 a,putting an increase load on the catheter 61 a. The increase in load onthe catheter 61 a may tend to straighten the catheter 61 a. In someembodiments, the drive assembly of the robotic system 10 maintains thebent shape of the catheter 61 a by tightening the control wire(s), whichhas the effect of stiffening the catheter 61 a. In some embodiments, therobotic system 10 is configured to detect the increased load on thecontrol wires (due to the placement of the sheath 62 a over the catheter61 a) to be detected. The operator, or the robotic system 10, can thenapply an equal counteracting load on all the control wires of thecatheter 61 a to ensure that its bent shape is maintained while thesheath 62 a is advanced over the bend. In other embodiments, the sheath62 a may be extremely flexible so that it does not put any significantload on the catheter 61 a as the sheath 62 a is advanced over thecatheter 61 a, and/or distort the anatomy.

Once the distal end of the catheter 61 a reaches the target location(FIG. 23C), the distal end of the catheter 61 a may be steered to createa bend so that the distal opening at the catheter 61 a faces towards atissue 2010 that is desired to be treated (FIG. 23D). The steering ofthe distal end of the catheter 61 a may be accomplished by receiving auser input at the workstation 2, which generates a user signal inresponse to the user input. The user signal is transmitted to thecontroller, which then generates a control signal in response to theuser signal. The control signal causes the drive assembly to applytension to one or more wires inside the catheter 61 a to thereby bendthe distal end of the catheter 61 a at the desired direction.

Next, the distal end 2300 of the elongate member 26 is deployed out ofthe lumen of the catheter 61 a by advancing the elongate member 26distally (FIG. 23E). This may be accomplished robotically using themanipulator 24, and/or manually. The sharp distal tip of the elongatemember 26 allows the distal end 2300 to penetrate into the target tissue2010. Also, the flexible section 320 of the elongate member 26 allowsthe elongate member 26 to follow the curvature of the catheter 61 a asthe elongate member 26 is advanced out of the lumen of the catheter 61a. In some embodiments, the distal advancement of the elongate member 26may be accomplished by receiving a user input at the workstation 2,which generates a user signal in response to the user input. The usersignal is transmitted to the controller, which then generates a controlsignal in response to the user signal. The control signal causes theelongate member manipulator 24 to turn its roller(s) to thereby advancethe elongate member 26 distally.

After the distal end 2300 of the elongate member 26 is desirablypositioned, the RF generator 350 is then activated to cause the distalend 2300 to deliver RF ablation energy to treat the target tissue 2010.In some embodiments, if the system 10 includes the return electrode 352that is placed on the patient's skin, the system 10 then delivers theenergy in a monopolar configuration. In other embodiments, if theelongate member 26 includes the two electrodes 370 a, 370 b, the system10 may then deliver the energy in a bipolar configuration. The energy isdelivered to the target tissue 2010 for a certain duration until alesion 2020 is created at the target site (FIG. 23E).

In some embodiments, while energy is being delivered by the elongatemember 26, cooling fluid may be delivered to the target site through thelumen in the elongate member 26, and out of the distal port 310 and/orside port(s) 312 at the elongate member 26. The cooling fluid allowsenergy to be delivered to the target tissue in a desired manner so thata lesion 3020 of certain desired size may be created. In otherembodiments, the delivery of cooling fluid is optional, and the methoddoes not include the act of delivering cooling fluid.

After the lesion 3020 has been created, the elongate member 26 may beremoved from the catheter 61 a, and a substance 2030 may then bedelivered to the target site through the lumen of the catheter 61 a(FIG. 23F). In some embodiments, the removal of the elongate member 26from the catheter 61 a may be accomplished by receiving a user input atthe workstation 2, which generates a user signal in response to the userinput. The user signal is transmitted to the controller, which thengenerates a control signal in response to the user signal. The controlsignal causes the elongate member manipulator 24 to turn its roller(s)to thereby retract the elongate member 26 proximally until the entireelongate member 26 is out of the lumen of the catheter 61 a.

In some embodiments, the substance 2030 may be an embolic material forblocking supply of blood to the target site. In other embodiments, thesubstance 2030 may be a drug, such as a chemotherapy drug, for furthertreating tissue at the target site. In further embodiments, thesubstance 2030 may be one or more radioactive seeds for further treatingtissue at the target site through radiation emitted from the radioactiveseed(s). In other embodiments, the delivery of the substance 2030 may beoptional, and the method may not include the act of delivering thesubstance 2030.

In some embodiments, if there is another target tissue (e.g., tumor)that needs to be treated, any or all of the above actions may berepeated. For example, in some embodiments, after the first tumor hasbeen ablated, the distal end of the catheter 61 a may be steered topoint to another direction, and the elongate member 26 may be deployedout of the catheter 61 a again to ablate the second tumor. Also, inother embodiments, the catheter 61 a may be moved distally or retractedproximally along the length of the vessel 2000 to reach different targetsites.

In other embodiments, instead of the telescopic configuration, therobotic system 10 may be configured to drive the catheter 61 a and thesheath 62 a in other configurations. For example, in some embodiments,the sheath 62 a may be bent and acts as guide for directing the catheter61 a to move in a certain direction. In such cases, the robotic system10 may be configured to relax the wires in the catheter 61 a so that thecatheter 61 a is flexible as it is advanced distally inside the lumen ofthe sheath 62 a. Also, in other embodiments, the sheath 62 a may not beinvolved in the method. In such cases, the robotic system 10 may beconfigured to drive the catheter 61 a without the sheath 62 a to advancethe catheter 61 a through the vasculature of the patient.

Also, in other embodiments, a guidewire may be used in combination withthe catheter 61 a and/or the sheath 62 a for advancement of the catheter61 a and/or the sheath 62 a inside the vessel of the patient. In suchcases, the elongate member 26 is not inserted into the catheter 61 a.Instead, the guidewire is coupled to the elongate member manipulator 24,and the guidewire is placed inside the lumen of the catheter 61 a. Themanipulator 24 may then be used to drive the guidewire to advance and/orretract the guidewire. In some cases, the robotic system 10 may advancethe guidewire, the catheter 61 a, and the sheath 62 a in a telescopicconfiguration, as similarly discussed.

If a guidewire is initially used to access the interior of the patient,the guidewire may be later exchanged for the elongate member 26. Forexample, in some embodiments, the guidewire may be exchanged for theelongate member 26 after initial access of the main hepatic artery (orvein). After the distal end of the catheter 61 a reaches the targetsite, the guidewire may then be removed from the lumen of the catheter61 a, and decoupled from the elongate member manipulator 24. Theproximal end of the elongate member 26 is coupled to the elongate membermanipulator 24, and the elongate member 26 is then inserted into thelumen of the catheter 61 a. The elongate member manipulator 24 is thenused to drive the elongate member 26 distally until the distal end 2300of the elongate member 26 exits out of the distal end of the catheter 61a, as similarly discussed.

In further embodiments, the elongate member 26 may not be needed totreat tissue. For example, in other embodiments, after the distal end ofthe catheter 61 a is desirably placed at a target site, the catheter 61a may then be used to deliver a substance (e.g., an agent, a drug,radioactive seed(s), embolic material, etc.) to treat tissue at thetarget site without ablating the tissue. In some embodiments, thecatheter 61 a itself may be directly used to deliver the substance. Inother embodiments, another delivery device (e.g., a tube) may be placedinside the lumen of the catheter 61 a, and the delivery device is thenused to deliver the substance. In such cases, the catheter 61 a is usedindirectly for the delivery of the substance.

In some embodiments, during the treatment method, a localizationtechnique may be employed to determine a location of the instrumentinside the patient's body. The term “localization” is used in the art inreference to systems for determining and/or monitoring the position ofobjects, such as medical instruments, in a reference coordinate system.In one embodiment, the instrument localization software is a proprietarymodule packaged with an off-the-shelf or custom instrument positiontracking system, which may be capable of providing not only real-time ornear real-time positional information, such as X-Y-Z coordinates in aCartesian coordinate system, but also orientation information relativeto a given coordinate axis or system. For example, such systems canemploy an electromagnetic based system (e.g., using electromagneticcoils inside a device or catheter body). Other systems utilize potentialdifference or voltage, as measured between a conductive sensor locatedon the pertinent instrument and conductive portions of sets of patchesplaced against the skin, to determine position and/or orientation. Inanother similar embodiment, one or more conductive rings may beelectronically connected to a potential-difference- basedlocalization/orientation system, along with multiple sets, preferablythree sets, of conductive skin patches, to provide localization and/ororientation data. Additionally, “Fiberoptic Bragg grating” (“FBG”)sensors may be used to not only determine position and orientation databut also shape data along the entire length of a catheter or shapeableinstrument. In other embodiments, imaging techniques may be employed todetermine a location of the instrument inside the patient's body. Forexamples, x-ray, ultrasound, computed tomography, MRI, etc., may be usedin some embodiments.

In other embodiments not comprising a localization system to determinethe position of various components, kinematic and/or geometricrelationships between various components of the system may be utilizedto predict the position of one component relative to the position ofanother. Some embodiments may utilize both localization data andkinematic and/or geometric relationships to determine the positions ofvarious components. The use of localization and shape technology isdisclosed in detail in U.S. patent application Ser. Nos.: 11/690,116,now abandoned, 11/176,598, now abandoned, 12/012,795, now abandoned,12/106,254, issued as U.S. Pat. No. 8,050,523 on Nov. 1, 2011,12/507,727, now abandoned, 12/822,876, issued as U.S. Pat. No. 8,460,236on Jun. 11, 2013, 12/823,012, now abandoned, and 12/823,032, issued asU.S. Pat. No. 8,672,837 on Mar. 18, 2014, the entirety of all of whichis incorporated by reference herein for all purposes.

Also, in one or more embodiments described herein, the system mayfurther include a sterile barrier positioned between the drive assemblyand the elongate member holder, wherein the drive assembly is configuredto transfer rotational motion, rotational motion, or both, across thesterile barrier to the rotary members to generate the correspondinglinear motion of the elongate member along the longitudinal axis of theelongate member, rotational motion of the elongate member about thelongitudinal axis, or both linear motion and rotational motion.

As illustrated in the above embodiments, the robotic technique andsystem 10 for treating liver tissue is advantageous because it allowsthe ablation device to reach certain part(s) of the liver through thevessel that may otherwise not be possible to reach using conventionalrigid ablation probe. For example, in some embodiments, using therobotic system 10 and the above technique may allow the distal end ofthe elongate member 26 to reach the lobus quatratus or the lobusspigelii of the liver, which may not be possible to reach byconventional ablation probe. Also, using the elongate member manipulator24 to position the elongate member 26 is advantageous because it allowsaccurate positioning of the distal end 2300 of the elongate member 26.

V. Other Clinical Applications

The different driving modes and/or different combinations of drivingmodes are advantageous because they allow an elongate instrument(catheter 61 a, sheath 61 b, elongate member 26, or any combinationthereof) to access any part of the vasculature. Thus, embodiments of thesystem described herein may have a wide variety of applications. In someembodiments, embodiments of the system described herein may be used totreat thoracic aneurysm, thoracoabdominal aortic aneurysm, abdominalaortic aneurysm, isolated common iliac aneurysm, visceral arteriesaneurysm, or other types of aneurysms. In other embodiments, embodimentsof the system described herein may be used to get across any occlusioninside a patient's body. In other embodiments, embodiments of the systemdescribed herein may be used to perform contralateral gait cannulation,fenestrated endograft cannulation (e.g., cannulation of an aorticbranch), cannulation of internal iliac arteries, cannulation of superiormesenteric artery (SMA), cannulation of celiac, and cannulation of anyvessel (artery or vein). In further embodiments, embodiments of thesystem described herein may be used to perform carotid artery stenting,wherein the tubular member may be controlled to navigate the aorticarch, which may involve complex arch anatomy. In still furtherembodiments, embodiments of the system described herein may be used tonavigate complex iliac bifurcations.

In addition, in some embodiments, embodiments of the system describedherein may be used to deliver a wide variety of devices within apatient's body, including but not limited to: stent (e.g., placing astent in any part of a vasculature, such as the renal artery), balloon,vaso-occlusive coils, any device that may be delivered over a wire, anultrasound device (e.g., for imaging and/or treatment), a laser, anyenergy delivery devices (e.g., RF electrode(s)), etc. In otherembodiments, embodiments of the system described herein may be used todeliver any substance into a patient's body, including but not limitedto contrast (e.g., for viewing under fluoroscope), drug, medication,blood, etc. In one implementation, after the catheter 61 a (leader) isplaced at a desired position inside the patient, the catheter 61 a andthe elongate member 26 may be removed, leaving the sheath 61 b toprovide a conduit for delivery of any device or substance. In anotherimplementation, the elongate member 26 may be removed, leaving thecatheter 61 a to provide a conduit for delivery of any device orsubstance. In further embodiments, the elongate member 26 itself may beused to deliver any device or substance.

In further embodiments, embodiments of the system described herein maybe used to access renal artery for treating hypertension, to treatuterine artery fibroids, atherosclerosis, and any peripheral arterydisease. Also, in other embodiments, embodiments of the system describedherein may be used to access the heart. In some embodiments, embodimentsof the system may also be used to deliver drug or gene therapy.

In still further embodiments, embodiments of the system described hereinmay be used to access any internal region of a patient that is notconsidered a part of the vasculature. For example, in some cases,embodiments of the system described herein may be used to access anypart of a digestive system, including but not limited to the esophagus,liver, stomach, colon, urinary tract, etc. In other embodiments,embodiments of the system described herein may be used to access anypart of a respiratory system, including but not limited to the bronchus,the lung, etc.

In some embodiments, embodiments of the system described herein may beused to treat a leg that is not getting enough blood. In such cases, thetubular member may access the femoral artery percutaneously, and issteered to the aorta iliac bifurcation, and to the left iliac.Alternatively, the tubular member may be used to access the right iliac.In one implementation, to access the right iliac, the drive assembly maybe mounted to the opposite side of the bed (i.e., opposite from the sidewhere the drive assembly is mounted in FIG. 1). In other embodiments,instead of accessing the inside of the patient through the leg, thesystem may access the inside of the patient through the arm (e.g., foraccessing the heart).

In any of the clinical applications mentioned herein, the telescopicconfiguration of the catheter 61 a and the sheath 61 b (and optionallythe elongate member 26) may be used to get past any curved passage wayin the body. For example, in any of the clinical applications mentionedabove, a guidewire placed inside the catheter 61 a may be advancedfirst, and then followed by the catheter 61 a, and then the sheath 61 b,in order to advance the catheter 61 a and the sheath 61 b distally pasta curved (e.g., a tight curved) passage way. Once a target location isreached, the guidewire may be removed from the catheter 61 a, and theelongate member 26 may optionally be inserted into the lumen of thecatheter 61 a. The elongate member 26 is then advanced distally untilits distal exits from the distal opening at the catheter 61 a. In otherembodiments, the catheter 61 a may be advanced first, and then followedby the sheath 61 b, in order to advance the catheter 61 a and the sheath61 b distally past a curved (e.g., a tight curved) passage way. In stillfurther embodiments, the guidewire may be advanced first, and thenfollowed by the catheter 61 a the sheath 61 b (i.e., simultaneously), inorder to advance the catheter 61 a and the sheath 61 b distally past acurved (e.g., a tight curved) passage way.

Each of the individual variations described and illustrated herein hasdiscrete components and features which may be readily separated from orcombined with the features of any of the other variations. Modificationsmay be made to adapt a particular situation, material, composition ofmatter, process, process act(s) or step(s) to the objective(s), spiritor scope of the present application. Also, any of the features describedherein with reference to a robotic system is not limited to beingimplemented in a robotic system, and may be implemented in anynon-robotic system, such as a device operated manually.

Methods recited herein may be carried out in any order of the recitedevents which is logically possible, as well as the recited order ofevents. Furthermore, where a range of values is provided, everyintervening value between the upper and lower limit of that range andany other stated or intervening value in that stated range isencompassed. Also, any optional feature described may be set forth andclaimed independently, or in combination with any one or more of thefeatures described herein.

All existing subject matter mentioned herein (e.g., publications,patents, patent applications and hardware) is incorporated by referenceherein in its entirety except insofar as the subject matter may conflictwith that described herein (in which case what is present herein shallprevail). The referenced items are provided solely for their disclosureprior to the filing date of the present application. Nothing herein isto be construed as an admission that any claimed invention is notentitled to antedate such material by virtue of prior invention.

Reference to a singular item, includes the possibility that there areplural of the same items present. More specifically, as used herein andin the appended claims, the singular forms “a,” “an,” “said” and “the”include plural referents unless the context clearly dictates otherwise.It is further noted that the claims may be drafted to exclude anyoptional element. As such, this statement is intended to serve asantecedent basis for use of such exclusive terminology as “solely,”“only” and the like in connection with the recitation of claim elements,or use of a “negative” limitation. Unless defined otherwise, alltechnical and scientific terms used herein have the same meaning ascommonly understood by one of ordinary skill in the art in the field ofthis application.

Although particular embodiments have been shown and described, it willbe understood that they are not intended to limit the claimedinventions, and it will be obvious to those skilled in the art havingthe benefit of this disclosure that various changes and modificationsmay be made. The specification and drawings are, accordingly, to beregarded in an illustrative rather than restrictive sense. The claimedinventions are intended to cover alternatives, modifications, andequivalents.

1-16. (canceled)
 17. A method of steering a distal end of an elongatemember, comprising: determining a desired bending to be achieved by thedistal end of the elongate member; determining an amount of tension tobe applied to a steering wire located within the elongate member basedon the desired bending to be achieved; using an actuatable element toapply a torque to turn a rotary member that is detachably coupled to theactuatable element, the steering wire having one end is secured to therotary member and another end secured to the elongate member, whereinthe application of the torque by the actuatable element causes tensionto be applied to the steering wire; and using a sensor coupled to theactuatable element to sense a characteristic that corresponds with anamount of force or torque being applied by the actuatable element toturn the rotary member.
 18. The method of claim 17, wherein the act ofusing the actuatable element to apply the torque comprises increasingthe amount of force or torque being applied by the actuatable elementuntil the sensed characteristic indicates that the amount of tension atthe steering wire has been achieved.
 19. The method of claim 17, whereinthe sensor is coupled indirectly to the actuatable element through amechanical component.